I enjoy driving a big van, so I can fit my skis and board into the car for the drive up the mountain. And that's exactly what I'll do, unless I'm driving up with friends who snowboard, in which case I'll just bring my board. I'll just pull out whatever I feel like riding at the time. The parking lot is at the bottom of the lift, so I can always switch mid-day if I feel the urge. Generally, I use my skis for big snow days, mogul days, and for a fair majority of the time on other days. Snowboard comes out for low-coverage conditions, when all the moguls have been groomed over, and sometimes just for a change of scenery when there aren't any great snow conditions to call home about. Since I usually stay on tamer terrain on the board, it's a good way to rest up while still being out on the mountain.
I'm much more confident on skis, but I can still handle most of the mountain on my board. It's nice to have options that suit whatever I feel like doing on a particular day.